Raspberry PI 3 cheat sheet

0-intro.md

Raspian

• Latest Jessie Light : https://downloads.raspberrypi.org/raspbian_lite_latest
• default login/pass : pi/raspberry
• Minibian : https://minibianpi.wordpress.com/features
• expand filsystem : sudo resize2fs /dev/mmcblk0p2

JavaScript

• clean nvm setup : https://www.losant.com/blog/how-to-install-nodejs-on-raspberry-pi
• johnny-five : http://johnny-five.io/
• raspi-io pin infos : https://github.com/nebrius/raspi-io/wiki/Pin-Information
• NodeJS home automation framework https://pimatic.org/

Audio

apt-get install alsa-utils
modprobe snd_bcm2835
amixer cset numid=3 1
amixer sset PCM,0 90%

add dtparam=audio=on to /boot/config.txt add snd_bcm2835 to /etc/modules numid: 0=auto, 1=headphones, 2=hdmi.

Pinout

CLI

Useful commands for OSX

SD cards

write image

see disks : diskutil list

⚠️ careful with the DISK parameter, it wipes the disk

IMAGE=/path/to/image.img
DISK=/dev/rdisk3
sudo dd if=$IMAGE of=$DISK bs=8m

also : unzip -p sdcard.img.zip | sudo dd bs=1m of=<device>

or use ./prepare-disk.sh /path/to/image.img

• expand filsystem : sudo resize2fs /dev/mmcblk0p2

backup image

use `./backup-disk.sh

network

detect your rpi on the network : sudo nmap -sS 192.168.0.1/24

GPIO

apt-get install wiringpi
gpio mode 7 out
gpio write 7 1
gpio write 7 0

create a WiFi access point

https://frillip.com/using-your-raspberry-pi-3-as-a-wifi-access-point-with-hostapd/

backup-disk.sh

#!/bin/sh
# set -x
#
# Backup given disk to backup.img
# USAGE : ./backup-disk /dev/rdisk3
#

function accept {
    echo
    read -p "▶ $1 (yN) " -n 1 -r
    echo
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]
    then
        return 0
    fi
    return 1
}

function log {
    echo " $1"
}

function backup {
    DISK=$1
    log "☕  Backup $DISK to backup.img - press Ctrl+T to see progress"
    CMD="sudo dd if=$DISK of=./backup.img bs=8m"
    echo `eval $CMD`
}

function unmount {
    DISK=$1
    log "🔨  Unmount $DISK"
    diskutil unmountDisk $DISK
}

function launch {
    DISK=$1
    if accept " ⚠  backup $DISK to ./backup.img ?"
    then
        log "🚀  Launch operations on $DISK"
        unmount $DISK
        backup $DISK
        log "👌  Done !"
    fi
}

function listDevices {
    diskutil list | grep /dev/disk -A 2 | grep "0:"
}

function getDiskBySize {
    echo `eval "diskutil list | grep '*$1' | grep -oE \"[^ ]+\$\""`
}

function guessDevice {
    DEVICE=$(getDiskBySize "4.0 GB")
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "8.0 GB")
    fi
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "2.0 GB")
    fi
    if [[ $DEVICE ]]
    then
        # add /dev/r for raw access
        DEVICE="/dev/r$DEVICE"
    fi
    echo $DEVICE
}

DEVICE=$1

if [[ ! $DEVICE ]]
then
    listDevices
    log "Guess device..."
    DEVICE=$(guessDevice)
fi

if [[ ! $DEVICE ]]
then
    echo '😡 No disk detected, use backup-disk.sh /dev/XXX'
    echo '😡 Use diskutil list to check the device'
    exit 1
else
    launch $DEVICE
fi

prepare-disk.sh

#!/bin/sh
# set -x
#
# Write image to disk.
# USAGE : ./prepare-disk /path/to/image.img
#

function accept {
    echo
    read -p "▶ $1 (yN) " -n 1 -r
    echo
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]
    then
        return 0
    fi
    return 1
}

function log {
    echo " $1"
}

function write {
    DISK=$1
    log "☕  Writing $IMAGE to disk - press Ctrl+T to see progress"
    CMD="sudo dd if=$IMAGE of=$DISK bs=8m"
    echo `eval $CMD`
}

function unmount {
    DISK=$1
    log "🔨  Unmount $DISK"
    diskutil unmountDisk $DISK
}

function launch {
    DISK=$1
    if accept " ⚠  Reformat $DISK with $IMAGE ?"
    then
        log "🚀  Launch operations on $DISK"
        unmount $DISK
        write $DISK
        unmount $DISK
        log "👌  Done !"
    fi
}

function listDevices {
    diskutil list | grep /dev/disk -A 2 | grep "0:"
}

function getDiskBySize {
    echo `eval "diskutil list | grep '*$1' | grep -oE \"[^ ]+\$\""`
}

function guessDevice {
    DEVICE=$(getDiskBySize "4.0 GB")
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "8.0 GB")
    fi
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "7.9 GB")
    fi
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "7.7 GB")
    fi
    if [[ ! $DEVICE ]]
    then
        DEVICE=$(getDiskBySize "2.0 GB")
    fi
    if [[ $DEVICE ]]
    then
        # add /dev/r for raw access
        DEVICE="/dev/r$DEVICE"
    fi
    echo $DEVICE
}

IMAGE=$1

if [[ ! $IMAGE ]]
then
    echo 'USAGE: prepare-disk /path/to/image.img'
    exit 1
fi

listDevices
log "Guess device..."
DEVICE=$(guessDevice)

if [[ ! $DEVICE ]]
then
    echo '😡  No disk detected, use prepare-disk.sh /dev/XXX'
    echo '😡  Use diskutil list to check the device'
    exit 1
else
    launch $DEVICE
fi